ML15030A033

Letter from James Thigpen Notification of Potential Part 21 Nuclear Nonconformance Event Number 50703

ML15030A033
Person / Time
Site:	Susquehanna
Issue date:	01/20/2015
From:	Thigpen J Baldor Electric Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
50703
Download: ML15030A033 (4)

Text

Baldor Electric Company,,I ,I=,P. 0. Box 250, 4349 Avery Drive.....................

_Flowery Branch, GA 30542 USAA MEMBER OF THE ABB GROUP Tel 678.947.7350 January 20, 2015To: Document Control DeskUnited States Nuclear Regulatory Commission Washington, DC 20555

Dear Sir or Madam:

In accordance with Title 10, Code of Federal Regulations, Part 21,Baldor Electric is making Written and Final Notification asrequired by 10CFR21.21 for event #50703.A. Name and address of the individual informing the NRC.James ThigpenQuality Assurance ManagerBaldor Electric/Gainesville Motor Plant4349 Avery DriveFlowery Branch, Georgia 30506B. Identification of Basic Component being Supplied.

AC MotorC. Name of firm supplying basic component.

Baldor Electric/Gainesville Motor Plant4349 Avery DriveFlowery Branch, Georgia 30542D. Nature of the defect, deviation, or failure to comply.

Subject:

Nuclear Nonconformance Event Number 50703This is a reportable 10CFR21 notification because we believeit is possible that the 9 identified lE motors shipped byBaldor Electric, contain a design where the buildup oftolerances between the shaft journal, bearing cap and bracketcould potentially allow the bearing cap to cock in thebracket causing a 0.001" interference fit on one side of thecap in a worst case scenario.

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..... Baldor Electric Company9A LID O0 P. 0. Box 250, 4349 Avery DriveFlowery Branch, GA 30542 USAA MEMBER OF THE ABB GROUP Tel 678.947.7350 STEPS TAKEN TO PREVENT FUTURE OCCURRENCES A review was completed by design engineering to determine this design issue has only occurred for the BaldorSpecification ID #'s associated with Howden Part Number600287-28R,

• of which Baldor has only shipped the 10 motorsidentified below of which 9 remain in the customers possession.

Baldor has the remaining motor in our possession and it is being replaced with one using the revised designdeveloped as our corrective action response.

Baldor has notified Howden North America Inc. Company's Quality Assurance of our findings.

They have in turncontacted their customer, PPL Susquehanna, and determined all9 motors in their possession have been in service for over 24hours with no problems.

The design of the shaft/bearing cap radial clearance has beenincreased to correct the potential safety issue. Motor Billof materials for the effected Baldor designs have beenrevised to call for bearing cap part number 603295-74B on anyfuture shipment.

CONCLUSION The one motor that failed during initial customer testing isin process of being repaired or replaced with the newdesigned bearing cap.The revision of the design for Spec. ID's B505968, B656588,B782464, B952117 and B1092454 has been implemented andverified to be correct.The end user PPL Susquehanna has confirmed to Howden NorthAmerica Inc. that the remaining 9 motors have been in servicefor over 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with no problems, and therefore do notrequire any alteration to the bearing cap in order to performtheir intended use safely.D. The Discovery Date.October 29, 2014.

A MEMBER OF THE ABB GROUPE. The Quantity and Location of Motors Affected.

Baldor Electric CompanyP. 0. Box 250, 4349 Avery DriveFlowery Branch, GA 30542 USATel 678.947.7350 PART/COMPONENT NUMBER:Customer Customer Motor Serial # End User / Location StatusName PO #Howden 39679 B505968-010 T1 PPL Susquehanna Contacted North 44617 B656588-010 T1 PPL Susquehanna Todd.Gunvalson@Ho America Inc. B656588-010 T1 PPL Susquehanna wden.com and48105 B782464-010 T1 PPL Susquehanna confirmed all 9 motorsB782464-010 T2 PPL Susquehanna have been running in012747 LIl 1 B952117-010 T1 PPL Susquehanna service for over 24B952117-010 T2 PPL Susquehanna hours with noB952117-010 T3 PPL Susquehanna problems.

022355 B1092454-010 T1 PPL Susquehanna B1092454-010 T2 Baldor Electric Motor will ship toHowden with newdesign, new serialnumberF. The Corrective Action which has been completed.

Baldor has notified Howden North America's Quality Assurance

.of our findings on the motor returned to Baldor for 10CFR21evaluation.

A review was completed by design engineering todetermine this failure was due to a collection of events thatoccurred simultaneously, and if were to happen again, wouldresult in failure within hours of the motor being powered.Baldor's solution to this worst case scenario is to open theclearances of the shaft bore in the cap up from a 0.008"radial clearance by design, to the maximum 0.012" radialclearance for 1.5" fit length for UL XP standards.

This wouldeliminate any possibility of a rub while the cap is mounted inthe cap journal of the bracket.

All motors that have been inservice for more than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> do not require alteration ofthe bearing cap. Any others that have not been placed intoservice should have the opposite drive end bearing capreplaced to ensure this failure will not occur. Thecorrective action CAR-00451 Howden: Request for 10CFR21Evaluation for bearing lockdown was completed and closed on12/23/14.

Baldor initiated corrective action per Baldor CAR-00451 onDecember 15, 2014 which was completed and received finalapproval by James Thigpen QA manager Baldor. Finalverification of actions will be and verified for effectiveness by 3/23/2015.

A MEMBER OF THE ABB GROUPBaldor Electric CompanyP. 0. Box 250, 4349 Avery DriveFlowery Branch, GA 30542 USATel 678.947.7350 G. Other Information.

All motors that have been in service for more than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> do notrequire alteration of the bearing cap. Any others that have notbeen placed into service should have the opposite drive endbearing cap replaced with a newly designed cap (603295-74B) toensure this failure could not occur.Sincerely, mre~s Tge~nQuality Assurance

Manager, Gainesville Motor PlantBaldor Electric Co.